Cato the Younger (Marcus Porcius Cato Uticensis, 95 BC, Rome – April 46 BC, Utica) was a politician and statesman in the late Roman Republic, and a follower of the Stoic philosophy. He was known as Cato Minor to distinguish him from his great-grandfather (Cato the Elder). A noted orator, he had great moral integrity. He could not be bribed, and disliked the political corruption of the age. He is remembered for his stubbornness and for his lengthy conflict with Julius Caesar.

Plutarch tells a story about Cato's peers' immense respect for him, even at a young age. During a Roman ritual military game, called "Troy", in which all aristocratic teenagers participated as a sort of "coming of age" ceremony, a mock battle with wooden weapons was performed on horseback. While the child of one of Sulla's surrogates was chosen by the adult organizers to lead one of the "teams," the team refused to follow him because of his character, and when they were finally asked whom they would follow, the boys unanimously chose Cato.

Cato was a supporter of Pompey, and continued the fight after Pompey was dead. The anti-Caesar forces, known as the Optimates (roughly, the "Good Guys") were reinforced by forces from local rulers. They numbered about eight legions (40.000 men) plus sixty elephants. Caesar defeated the Optimates at the Battle of Thapsus in modern Tunisia, North Africa. Cato did not actually take part in the battle, which was led by a colleague, and committed suicide after the defeat. Roughly 10,000 enemy soldiers wanted to surrender to Caesar, but were instead slaughtered by his army. This action was unusual for Caesar, who was known as a merciful victor. No explanation of this is known.